Brought to you by Bayer Crop Science
'Weed control has become a big puzzle'
Contractor Hofmeijer in Voorst, Gelderland, provides after-sowing, equal sowing and under-sowing of catch crops in maize for customers. Weed control has therefore become a big puzzle.
"Two seasons ago, we simply checked the sowing dates and knew when to spray which customer. Now we need an extensive Excel schedule to be there on time everywhere. In addition, the number of spray mixes has also doubled from 2 to 4 and we have more additions for problem plots," says director Herbert Hofmeijer.
"Yes, in recent years it has been quite a search to integrate maize cultivation with under-sowing into our business operations. And my planner and I did not always agree on which method would work best for our area of work. So you can I can say that it was quite a puzzle.”
Herbert Hofmeijer looks back with a smile on the 'long run-up' to 2019, the first year with compulsory sowing of a catch crop. In addition to gaining knowledge on experimental farms and on trial plots, the contracting company also analyzed its own sowing, spraying and harvesting data from previous years, with the aim of finding connections that might lead to 1 'most suitable' maize cultivation system. "But we did not find those connections. We are in the central Netherlands and, with the earliness of the maize, we also hover somewhat in between. The ripening is too erratic and unpredictable to put forward 1 optimal cultivation systems. The only conclusion that What we were able to do was that every season is slightly different and that we therefore had to offer several cultivation and under-sowing options."
Undersow most commonly used
The contracting company currently provides about 760 hectares of maize for customers, of which about 200 hectares is on clay and 560 hectares on sandy soil. Last season, a green manure crop was sown on approximately 100 hectares of maize on sand (and the maize was therefore harvested before 1 October). Of the remaining 460 hectares, a catch crop (Italian or perennial ryegrass) was later undersown on about 400 hectares. On the other 60 hectares, maize and catch crop (reed fescue) were sown simultaneously.
According to Hofmeijer, the distribution was largely established during an information afternoon for growers. "We then asked what maize growers themselves would like, but soon noticed that most would like to leave it to us. An important parameter is the presence of smooth-finger grass. In fields where this is a problem, the option of sowing the same seed is more or less out of the question. Reed fescue suffers too much from agents that can combat smooth-fingered grass well.There is also a group of maize growers who have no problems with an early harvest, don't want to bother with undersowing or simply don't want to pay extra for it. sown in the usual way – without under-sowing. We applied under-sowing in by far the largest group, mainly with Italian ryegrass, but partly also with perennial ryegrass", sums up the contractor.
Weed control more customization
According to Hofmeijer, both level sowing and undersowing performed reasonably well last season. "The ryegrasses that were sown later had a hard time with the drought, but they were still able to develop to such an extent that after the maize harvest there was a 'just successful' patch of grass. We hardly saw any plots with only a few blades or no grass at all. We have not had any setbacks or disappointments." For the coming season, he therefore expects that only a number of growers will say goodbye to undersowing and switch to post-sowing a catch crop in combination with a (very) early maize variety.
With the advent of under-seeding, weed control has also become more customized than before. "In addition to the sowing date of maize and the weed situation in the field, we now also have to take the catch crop into account. These data – such as the grass type, the sowing date and the weather conditions that apply at that time – partly determine the spray mix," says Hofmeijer .
Last season, 4 different mixes were therefore used, of which 2 for the under-seeding systems and 2 for conventional maize cultivation without under-sowing.
Basic mix with Laudis
For maize cultivation with under-sowing, a basic mix with Laudis, Calaris®, Milagro® and Kart® was mainly chosen last season. "With this we can not only properly clean up common weeds, such as chanterelle, cranesbill and chervil, but we also tackle chamomile and smooth-fingered grass reasonably well. It is therefore a very nice basis, where we can use additional resources against specific weeds at will. can add," says Hofmeijer. Another nice plus is that this mix is safe for the catch crop and can therefore be used a week after undersowing. "That flexibility is very nice, especially now that we work with so many different cultivation systems."
For the coming season – in consultation with advisor and resource supplier Geert Schieven – the basic mix with Laudis, Calaris, Milagro and Kart has been chosen again. "It has worked well for us, so why should we do it differently now?", says Hofmeijer.
Calaris® and Milagro® are registered trademarks of Syngenta Kart® is a registered trademark of Corteva Agriscience
